Cellular telephones having a hinged cover, commonly known as a flip, are offered by several manufacturers. The hinged cover is movable between open and closed positions. In the closed position, the hinged cover extends over the keypad of the telephone. In the open position, the hinged cover provides a convenient extension to the phone and, when fitted with a microphone, is well positioned to receive audio input from the user's mouth. One problem with flips or hinged covers containing electrical components is the difficulty of interconnecting the remote electrical components and/or circuits in the flip to the transceiver electronics in the main body of the phone. One approach is to utilize flex circuits extending through the hinge to establish the necessary electrical connections. This approach, however, presents several disadvantages including concern about the durability of the flex circuit during high-cycle flexing, difficulty of assembly, and increased costs. Also, when antennas are integrated into the flip, R/F performance of the antenna can be adversely affected by the flex cable design unless carefully controlled impedance matching is included in designs.
Another method of connecting remote electronics in a hinged cover to the transceiver electronics in the main body of the phone is to use discrete wires routed through the hinge. The main problem with this approach is that the hinge is relatively small and thus only a limited number of cables or wires can be accommodated. Further, routing of RF signals through the hinge is difficult since coaxial cables are needed which require a large volume. A further problem is the difficulty of predicting and testing the life of a highly flexed cable assembly which is repeatedly twisted in this manner. Thus, this approach limits the number and type of electronics that can be placed on the hinged cover.
Another drawback of using flex cables or discrete wires to make electrical connections between the main body and hinged cover is that the hinged cover cannot be removed. This is a major concern since phones are frequently dropped. To prevent or repair damage to the flip, it is desirable to design the flip in such a way that the flip can be practically detached and reattached from the main body when exposed to excessive forces or replacement needs. When this occurs, the cabling or wiring may be pulled loose or otherwise damaged rendering the phone inoperable.
Accordingly, there is a need for a new method and apparatus for making an electrical connection between remote electronics contained in a hinged cover and transceiver electronics disposed in the main body of a radiotelephone.